The invention relates to an apparatus for membrane filtration comprising a vessel provided with a liquid inlet for the supply of liquids to be treated, a liquid outlet for the discharge of treated liquids and a permeate discharge tube, a plurality of supporting tubes surrounded by the vessel wall, each supporting tube supporting a non-woven tube, upon which a tubular filtration membrane is fixed and sealing members for sealing off the ends of each assembly of supporting tubes together with a nonwoven tube and a filtration membrane.
A similar device for membrane filtration, the perforated supporting tubes in the form of rigid plastic tubes being attached in openings of end plates, is known. As the supporting tubes are fixed in openings in plates, the supporting tubes are situated remote from each other at smaller or larger distances, but they never contact each other as this fixing of the supporting tubes does not allow for any contact.
In this known apparatus the permeate is discharged through a central permeate discharge tube being provided with bores, debouching into the free space of the vessel in which the supporting tubes are accommodated.